I'm trying to check if account exists using sqlite, I tried almost everything and I need help.
My Code:
function islinked(discordid, callback) {
const getdata = `SELECT EXISTS(SELECT 1 FROM capedata WHERE id = ?);`;
db.all(getdata, [discordid], (err,data)=>{
if (err) return console.error(err.message);
callback(data)
})
}
islinked(440877393616306200, callback => {
console.log(callback)
})
It returns:
[ { 'EXISTS(SELECT 1 FROM capedata WHERE id = ?)': 1 } ]
However I just want to get 1, how can I achieve this?
Related
Seems like a super basic task, but I just cannot get this to work (not very experienced with mongo or nodeJS).
I have an array of records. I need to check the DB to see if any records with a matching name already exist and if they do grab that record so I can update it.
Right now I am trying this
function hit_the_db(db, record_name, site_id) {
return new Promise((resolve, reject) => {
var record = db.collection('' + site_id + '_campaigns').find({name: record_name}).toArray(function(err, result) {
if (err) {
console.log('...error => ' + err.message);
reject(err);
} else {
console.log('...promise resolved...');
resolve(result);
}
});
console.log('...second layer of select successful, returning data for ' + record.length + ' records...');
return record;
});
}
This query works in another part of the app so I tried to just copy it over, but I am not getting any records returned even though I know there should be with the data I am sending over.
site_id is just a string that would look like ksdlfnsdlfu893hdsvSFJSDgfsdk. The record_name is also just a string that could really be anything but it is previously filtered so no spaces or special characters, most are something along these lines this-is-the-name.
With the names coming through there should be at least one found record for each, but I am getting nothing returned. I just cannot wrap my head around using mongo for these basic tasks, if anyone can help it would be greatly appreciated.
I am just using nodeJS and connecting to mongoDB, there is no express or mongoose or anything like that.
The problem here is that you are mixing callback and promises for async code handling. When you call:
var record = db.collection('' + site_id + '_campaigns').find({name: record_name}).toArray(function(err, result) {
You are passing in a callback function, which will receive the resulting array of mongo records in a parameter called result, but then assigning the immediate returned value to a variable called 'record', which is not going to contain anything.
Here is a cleaned up version of your function.
function hit_the_db(db, site_id, record_name, callback) {
// Find all records matching 'record_name'
db.collection(site_id + 'test_campaigns').find({ name: record_name }).toArray(function(err, results) {
// matching records are now stored in 'results'
if (err) {
console.log('err:', err);
}
return callback(err, results);
});
}
Here is optional code for testing the above function.
// This is called to generate test data
function insert_test_records_callback(db, site_id, record_name, insert_count, callback) {
const testRecords = [];
for (let i = 0; i < insert_count; ++i) {
testRecords.push({name: record_name, val: i});
}
db.collection(site_id + 'test_campaigns').insertMany(testRecords, function(err, result) {
return callback(err);
});
}
// This cleans up by deleting all test records.
function delete_test_records_callback(db, site_id, record_name, callback) {
db.collection(site_id + 'test_campaigns').deleteMany({name: record_name}, function(err, result) {
return callback(err);
});
}
// Test function to insert, query, clean up test records.
function test_callback(db) {
const site_id = 'ksdlfnsdlfu893hdsvSFJSDgfsdk';
const test_record_name = 'test_record_callback';
// First call the insert function
insert_test_records_callback(db, site_id, test_record_name, 3, function(err) {
// Once execution reaches here, insertion has completed.
if (err) {
console.log(err);
return;
}
// Do the query function
hit_the_db(db, site_id, test_record_name, function(err, records) {
// The query function has now completed
console.log('hit_the_db - err:', err);
console.log('hit_the_db - records:', records);
delete_test_records_callback(db, site_id, test_record_name, function(err, records) {
console.log('cleaned up test records.');
});
});
});
}
Output:
hit_the_db - err: null
hit_the_db - records: [ { _id: 5efe09084d078f4b7952dea8,
name: 'test_record_callback',
val: 0 },
{ _id: 5efe09084d078f4b7952dea9,
name: 'test_record_callback',
val: 1 },
{ _id: 5efe09084d078f4b7952deaa,
name: 'test_record_callback',
val: 2 } ]
cleaned up test records.
I need to get the last id from my database table, so I have to use MAX in order to achieve it, so this is the sql query I am using: SELECT MAX(id) FROM payments
The issue comes when I try to get the value from the object as it throws this error: id is not defined
server.js:
app.post('/sendMail', function(req, res) {
getLastPaymentId().then((data) => {
lastPaymentId = data.lastPaymentId;
console.log(lastPaymentId.MAX(id)); //here I want to get the value
});
res.redirect('/');
});
function getLastPaymentId() {
const idPayment = new Promise((resolve, reject) => {
dbConnection.getLastPaymentId().then(data => {
resolve(data)
})
});
return Promise.all([idPayment]).then(data => {
return {
lastPaymentId: data[0]
}
})
}
dbConnection.js:
function getLastPaymentId() {
return new Promise(function(resolve, reject) {
const sql = "SELECT MAX(id) FROM payments";
con.query(sql, function(err, result) {
if(err) throw err;
resolve(result);
});
});
}
module.exports.getLastPaymentId = getLastPaymentId;
Result when just printing the object (console.log(lastPaymentId)):
It is null because I have no rows in my database yet.
Result when printing the value (console.log(lastPaymentId.MAX(id))):
It should print null instead.
How can I fix this?
Fixed! I have just remembered that I had a similar issue in the past and the answer I got, has worked in this case as well: How to access to the value when doing a COUNT() using node-mysql?
Sorry and thanks anyway!
I know that on robomongo if I want to find _id of user where username = test2 I can use
db.getCollection('user').find({},{_id:1},{"username":"test2"})
now, on visual studio code, I want to find value of field "disabled" from user collection where field "username" value equal to variable "tempusername" value. I tried:
colUser = mongoDb.collection("user");
var status = colUser.find({},
{ disabled:1},{ username:tempusername},function (err, doc) {
console.log(doc);
});
but it shows value of status is "undefined". What is the write code for this?
I think it's something you're looking for.
const url = 'mongodb://localhost:27017'
MongoClient.connect(url, (err, db) => {
const dbo = db.db('mydb')
dbo.collection('user').find({disabled:'1',username:tempusername}).toArray((err, doc) => {
if(err){
console.log(err)
}
console.log(doc)
db.close()
})
})
I found the answer, basically the way it work is the result will be return inside the function, so I have to put it like this:
var statusbuffer;
colUser.findOne({ username:tempusername},{ _id:0,disabled:1},function (err, userstatus){
// User result only available inside of this function!
if (err) {
next("Failed to update records");
} else {
console.log("disabled status here:",userstatus.disabled) // => yields your user results
statusbuffer = userstatus.disabled;
next();
}
});
thanks all for your comments!
I want to return the data which is generated in the PostgreSQL query result of getData()function, in console 1 i am getting the expected result but it is unable to access outside the query function i mean in console 2 am getting empty array. it should be able to access in my 2nd function called getFun()
i want to get the console 1 value from getData() to getFun().
can some one help me please.
Here is my code:
function getData(value){
var array = [];
db.query('select * from users where _id = $1', [value], function(err, result) {
array.push(result.rows);
console.log('1',array);
})
console.log('2', array);
}
exports.getFun = function(data, callback) {
employee.find({
'company_id':parseInt(data.company_id)
}).sort({
"times.date": -1
}).toArray().then(function(timers) {
_.each(timers.list, function(s) {
var display = getData(s.user_id);
console.log('3',display);
})
}).catch(function(error) {
console.log(error);
})
}
I am trying write a cron function in nodejs which fetches user_ids of all the users from the db and then I want to parse through each user_id.
Here is my code :
cron.schedule('43 11 * * *', function(){
var now = moment()
var formatted = now.format('YYYY-MM-DD HH:mm:ss')
console.log('Starting the cron boss!');
var dbSelectPromise = function(db, sql1) {
return new Promise(function(resolve, reject) {
db.select(sql1, function(err, data) {
if (err) {
reject(err)
} else {
resolve(data)
}
})
})
}
var users =[]
var sql = "select distinct(user_id) from user_level_task"
dbSelectPromise(db,sql).then(function(secondResult){
for(i=0;i<secondResult.length;i++){
var sql1 = "select max(level_id) as level from user_level_task where user_id ="+secondResult[i].user_id
dbSelectPromise(db,sql1).then(function(thirdResult){
console.log(thirdResult)
console.log(current)
var sql2 = "select task_id form user_level_task where user_id = '"+secondResult[i].user_id+"' and level_id = '"+thirdResult[0].level+"' "
dbSelectPromise(db,sql2).then(function(fourthResult){
var leng = fourthResult.length
for(i=0;i<leng;i++){
console.log(fourthResult[i])
}
})
})
}
})
});
The problem i am facing is i cannot access value of i in third and fourth promises. Please help!
I think what's happening is that i is no longer the same when you create those new promises because the for loop is still running. It appears that what you really need is the user_id and level_id. I suggest you restructure your code a bit to reduce nesting and pass on the values you need for future promises.
Perhaps something similar to this:
dbSelectPromise(db, sql)
.then(secondResult => {
const levelPromises = [];
secondResult.forEach(res => {
levelPromises.push(getLevelByUserId(res.user_id, db));
});
return Promise.all(levelPromises); // Promise.all only if you want to handle all success cases
})
.then(result => {
result.forEach( level => {
{ userId, queryResult } = level;
// ...
})
//...
})
.catch(err => {
console.log(err);
});
function getLevelByUserId(userId, db) {
const query = `select max(level_id) as level from user_level_task where user_id = ${userId}`;
return dbselectPromise(db, query).then(result => { userId, result });
}
It creates an array of all the get level queries as promises and then passes it along to the next step using Promise.all() which will only resolve if all queries were successful. At that point, you will have access to the userId again of each result because we returned it in our new function for your next set of queries.
I think you should abstract your queries a bit further instead of using a generic dbSelectPromise and don't forget to catch() at the end otherwise you won't know what's happening.
Note: It assumes your db variable instantiated properly and your original db.select doesn't need to be returned based on whatever library you're using. There's also some new syntax there.
The problem i am facing is i cannot access value of i in third and fourth promises. Please help!
This is because you're using reinitializing i without using let. When the loop is in process, the value will be different than what you expect.
each promise is dependant on the other and need to run synchronously
For this to work, You need to chain promises. Also, you can make use of Promise.all() to execute a bunches of promises at once. Remember, Promise.all() is all or nothing.
Making those changes to your code, I get the following structure.
'use strict';
let _ = require('lodash');
function dbSelectPromise(db, sql1) {
return new Promise((resolve, reject) => {
return db.select(sql1, (err, data) => {
if (err) {
return reject(err);
}
return resolve(data);
});
});
}
function process(secondResult) {
let sql1 = "select max(level_id) as level from user_level_task where user_id =" + secondResult[i].user_id;
return dbSelectPromise(db, sql1).then(function (thirdResult) {
console.log(thirdResult);
let sql2 = "select task_id form user_level_task where user_id = '" + secondResult[i].user_id + "' and level_id = '" + thirdResult[0].level + "' ";
return dbSelectPromise(db, sql2);
});
}
function getUsers() {
let sql = "select distinct(user_id) from user_level_task";
return dbSelectPromise(db, sql).then((users) => {
return users;
}).catch(() => {
return [];
});
}
cron.schedule('43 11 * * *', function () {
var now = moment();
var formatted = now.format('YYYY-MM-DD HH:mm:ss');
getUsers().then((users) => {
let batches = _.map(users, function (user) {
return process(user);
});
return Promise.all(batches);
}).then((fourthResult) => {
console.log('Your fourthResult [[],..]', fourthResult);
}).catch(() => {
console.log('err while processing', err);
});
});